182 THE MALAYAN PAPILIONIDE AS 
have a very weak and slow flight, and do not seek 
concealment, or appear to have any means of protec- 
tion from insectivorous creatures. It is natural to 
conclude, therefore, that they have some hidden pro- 
perty which saves them from attack; and it is easy 
to see that when any other insects, by what we call 
accidental variation, come more or less remotely to 
resemble them, the latter will share to some extent in 
their immunity. An extraordinary dimorphic form of 
the female of Papilio Ormenus has come to resemble 
the Drusillas sufficiently to be taken for one of that 
group at alittle distance; and it is curious that I cap- 
tured one of these Papilios in the Aru Islands hovering 
along the ground, and settling on it occasionally, just 
as it is the habit of the Drusillas todo. The resem- 
blance in this case is only general; but this form of 
Papilio varies much, and there is therefore material 
for natural selection to act upon, so as ultimately to 
produce a copy as exact as in the other cases. 
The eastern Papilios allied to Polydorus, Coon, 
and Philoxenus, form a natural section of the genus 
resembling, in many respects, the Aineas-group of 
South America, which they may be said to represent 
in the East. Like them, they are forest insects, 
have a low and weak flight, and in their favourite 
localities are rather abundant in individuals; and like 
them, too, they are the objects of mimicry. We may 
conclude, therefore, that they possess some hidden 
means of protection, which makes it useful to other 
insects to be mistaken for them. 
